1. Field of the Invention
The present invention relates to a droplet jetting applicator which jets droplets to an application object and a method of manufacturing a coated body using the droplet jetting applicator.
2. Discussion of the Background
A droplet jetting applicator is usually used to manufacture various types of displays such as a liquid crystal display, an organic electroluminescence display, an electron-emitter display, a plasma display, and an electrophoretic display.
The droplet jetting applicator includes a droplet jetting head (for example, an inkjet head) which jets droplets (for example, ink) from a plurality of nozzles to an application object. Such a droplet jetting applicator causes droplets to land on a substrate as the application object by means of the droplet jetting head to form rows of dots of a predetermined pattern, thus manufacturing a coated body, for example, such as a color filter or a black matrix (a frame of the color filter). At this time, a substrate holding table on which the substrate is placed and the droplet jetting head move relatively.
In such a droplet jetting applicator, ink at tips of the nozzles coagulates and clogs the nozzles during a non-droplet jet operation such as transportation of the substrate or an alignment operation, or foreign articles such as dust adhere around the tips of the nozzles. Moreover, even during a droplet jet operation, splashed ink and the like adhere to a nozzle surface. This causes bad jet such as non-jet or curved flight of the droplets.
To prevent such clogging of the nozzles and adherence of foreign articles around the tips of the nozzles, therefore, a droplet jetting applicator has been proposed, which performs a redundant jet operation to redundantly jet droplets by means of the droplet jetting head. Moreover, in order to remove foreign articles on the nozzle surface, a droplet jetting applicator has been proposed, which blows air onto the nozzle surface while controlling the strength of the airflow (for example, see JP-A No. 2004-174845(KOKAI)).
In the droplet jetting applicator which performs the redundant jet operation, usually, an absorption pad which receives and absorbs droplets jetted by the droplet jetting head is provided in adjacent to a substrate holding table, above which a guide plate supporting and guiding the droplet jetting head is laid. In a maintenance operation, the droplet jetting head is guided by the guide plate to move to the position facing an absorption pad for the redundant jet operation.
However, in the droplet jetting applicator which performs the aforementioned redundant jet operation, it is necessary to make a space for the absorption pad to be placed in adjacent to the substrate holding table, which increases the droplet jetting applicator in size. Especially when the droplet jetting applicator includes a plurality of the droplet jetting heads, it is necessary to arrange the same number of the absorption pads as that of the droplet jetting heads, which increases the droplet jetting applicator in size. Furthermore, in order to move the droplet jetting head to the position facing the absorption pad, the guide plate needs to be extended to the position facing the absorption pad and increases in length. The droplet jetting applicator accordingly increases in size.
Moreover, in the above-described droplet jetting applicator which blows air onto the nozzle surface, the redundant jet operation is not performed, and the air is blown onto the nozzle surface. Accordingly, drying of ink at the nozzle tips is accelerated. The ink at the nozzle tips coagulates, and nozzles are subject to clogging.